The present invention relates to a camera having a built-in flash.
Recently, with the progress of automatic mechanization in the field of single-lens reflex cameras, various cameras including an autofocusing device and a built-in flash have been proposed.
An example of such an autofocusing device is described in U.S. Pat. No. 4,801,963 to Koyama et al, wherein the focus condition of the camera lens is determined based on the contrast of an image transmitted through the lens of the positional relationship (often referred to as a phase difference) between images or image portions transmitted through the lens. If the lighting conditions or object contrast are low, there may be insufficient light or insufficient contrast for the image sensors to operate effectively. Accordingly, Koyama et al provides an auxiliary spotlight projector for radiating a contrast pattern (stripe pattern) toward the object during conditions of low light or low contrast. However, Koyama et al provides the auxiliary spotlight projector separately, and their remains a problem as to how to secure a space for the auxiliary spotlight projector in the single-lens reflex camera having a limited space.
Also, a single-lens reflex camera has an object within a range of from a close-up distance to an infinite distance as its aim. An optimum focal-length lens is selected corresponding to the kind of the subject and the distance from the subject. The cylinder length of the interchangeable lens is enlarged corresponding to the focal length thereof. Recently, with the advance of zoom lenses, photographers ordinarily using such zoom lenses to cover from wide-angle lenses to telephoto lenses, instead of conventional fixed-focal-length interchangeable lenses, have increased in number. Generally, the minimum cylinder length of the zoom lens is at the maximum focal length. Accordingly, if the zoom lens is shifted to the minimum focal length, the cylinder length is not so shortened.
Therefore, in the case where a built-in flash mechanism is incorporated in a single-lens reflex camera, it becomes important to design the camera to prevent flashlight from being blocked by the lens cylinder.
Also, in a conventional built-in flash, the flash is held in the housing position by a lock mechanism for causing a pin provided linkage mechanism to engage with a hook provided or the camera body. However, the lock mechanism has a disadvantage as follows. When pressure is applied to the light emission portion to move down to the housing position and then released after the pin has engaged with the hook, the light emission portion slightly moves in the direction reverse to the pressure or in other words slightly returns toward the projecting position because a clearance always arises between the pin and the hook. For this reason, a slight space arises between the opening line portion of the housing chamber and the ceiling plate.
Such a space gives the user an unfavorable impression of the outside appearance and handling properties of the camera as a precision machine.
Also, there are two types of built-in flashes in cameras, that is, of the stationary type and of the housing type. The conventional housing type built-in flash is arranged such that a flash unit urged by a spring means in the direction of projection is normally kept at a housing position by a stoppage/engagement means so that the flash unit can be moved to a projecting position by removing the stoppage/engagement in use. Therefore, a shock due to projection was unavoidable and, further, good operational feeling could not be attained. In addition, there is no denying the fact that the shock has a bad influence upon the camera which is a precision instrument. In addition, according to the conventional housing type built-in flash, the light emission surface of the flash unit could not be moved to the bouncing position where the light emission surface looked more upward than the direction toward the subject. If bounce-photographing was necessary, it was necessary to use another outside flash.